The capsule—about four meters long and three meters in diameter when inflated—is made of a proprietary flexible fabric that the company says can provide better protection from radiation and space debris than the metal parts of the ISS can. Its two-year maiden voyage will be a critical test of that claim. If successful, it opens the door for sending more such modules into space, and strengthens the argument for Bigelow’s technology to be used on a mission to Mars.

The folded-up BEAM being loaded into SpaceX's Dragon capsule in preparation for launch.

The successful launch today marks a first for inflatable spacecraft, but it was also an important first for SpaceX. The company managed to safely land its Falcon 9 rocket on an unmanned ship in the Atlantic Ocean, a major step toward reusing its launch vehicles on subsequent missions and lowering the cost of spaceflight.